On load events
Depending on your UA implementation you may have EEC logic that is picked up by the pageview tag. These on-load dataLayer objects don’t always require an event value pair and work efficiently with the pageview tag. From what I’ve seen, this same approach can’t be used for GA4 as the configuration tag doesn’t contain the same logic to take the data layer object and combine it with the pageview. So, if you want to be able to convert other EEC tags like promo views, impressions, detail, and checkout steps you will first require a change in the dataLayer.
Summary
It’s quite easy to rebuild your enhanced eCommerce product array for GA4 using the EEC builder template and I would recommend everyone to run GA4 in tandem with UA as the product continues to mature.
If you have any questions or would like to just chat do get in touch.